The present invention relates to aerosol delivery articles, and in particular, to such articles which are capable of providing aerosol particles of relatively small size while subjecting the material to be aerosolized to relatively low temperatures.
It has been desirable to deliver certain medications to a patient in vapor or aerosol form. As such, the patient inhales the medication, and that medication directly enters that patient's respiratory system. See, Science, Vol. 260, p. 912 (1993). As a result, there have been efforts towards developing various aerosol delivery devices, principally for the delivery of certain pharmaceutical compositions or drugs. As used herein, the term "drug" includes articles and substances intended for use in the diagnosis, cure, mitigation, treatment or prevention of disease; and other substances and articles referred to in 21 U.S.C. .sctn.321(g)(1). Certain aerosol delivery articles and articles for delivering medicaments in vapor form are described in U.S. Pat. No. 1,771,366 to Wyss et al.; U.S. Pat. No. 1,968,509 to Tiffany; U.S. Pat. No. 2,030,075 to Robinson; U.S. Pat. No. 2,057,353 to Whittemore, Jr.; U.S. Pat. No. 3,820,540 to Hirtz et al.; U.S. Pat. No. 4,036,224 to Choporis et al.; U.S. Pat. No. 4,214,146 to Schimanski; U.S. Pat. No. 4,303,083 to Burruss, Jr.; U.S. Pat. No. 4,735,217 to Gerth et al.; U.S. Pat. No. 4,922,901 to Brooks et al.; and U.S. Pat. No. 4,941,483 to Ridings et al.; as well as by Hickey in Drugs Pharm. Sci., Vol. 54, p.255 (1992). Certain other delivery articles are described in U.S. Pat. No. 3,297,029 to Brinkman et al.; U.S. Pat. No. 3,859,398 to Havstad; U.S. Pat. No. 3,864,544 to Van Amerongen; U.S. Pat. No. 3,990,441 to Hoyt et al.; U.S. Pat. No. 4,190,046 to Virag and U.S. Pat. No. 4,523,589 to Krauser.
Certain of the aerosol delivery articles provide medication in aerosol form by mechanical action. In particular, the medication is provided in the form of an aerosol using nebulizers and metered dose inhalers. Such aerosol delivery articles are desirable in that the pharmacological composition to be aerosolized is not subjected to exposure to heat and high temperatures. However, mechanically generated aerosols typically comprise significant numbers of particles of relatively large size (i.e., greater than about 5 .mu.m in diameter). Such large size particles do not always provide the pharmaceutical composition in a form which provides for maximum effectiveness in treating the patient. Aerosol delivery articles which employ heat to evaporate aerosol forming materials which later condense into aerosol particles of relatively small size provide aerosols which are readily inhaled. However, the pharmacological properties of certain pharmaceutical compositions which are aerosolized by vaporization often are undesirably altered, because certain pharmaceutical compositions are quite sensitive to the effects of heat and temperature.
It would be desirable to provide an aerosol delivery article which is capable of producing aerosol particles of relatively small size (e.g., submicron size) without the necessity of subjecting the material to be aerosolized to exposure to a significant degree of heat or high temperatures.